#! /usr/bin/env python
# encoding: UTF-8
# Petar Forai
# Thomas Nagy 2008-2010 (ita)

import re
from waflib import Task, Utils, Logs
from waflib.TaskGen import extension, feature, after_method
from waflib.Configure import conf
from waflib.Tools import c_preproc

"""
tasks have to be added dynamically:
- swig interface files may be created at runtime
- the module name may be unknown in advance
"""

SWIG_EXTS = ['.swig', '.i']

re_module = re.compile('%module(?:\s*\(.*\))?\s+(.+)', re.M)

re_1 = re.compile(r'^%module.*?\s+([\w]+)\s*?$', re.M)
re_2 = re.compile('%include "(.*)"', re.M)
re_3 = re.compile('#include "(.*)"', re.M)

class swig(Task.Task):
  color = 'BLUE'
  run_str = '${SWIG} ${SWIGFLAGS} ${SWIGPATH_ST:INCLUDES} ${DEFINES_ST:DEFINES} ${SRC}'
  ext_out = ['.h'] # might produce .h files although it is not mandatory

  def runnable_status(self):
    for t in self.run_after:
      if not t.hasrun:
        return Task.ASK_LATER

    if not getattr(self, 'init_outputs', None):
      self.init_outputs = True
      if not getattr(self, 'module', None):
        # search the module name
        txt = self.inputs[0].read()
        m = re_module.search(txt)
        if not m:
          raise ValueError("could not find the swig module name")
        self.module = m.group(1)

      swig_c(self)

      # add the language-specific output files as nodes
      # call funs in the dict swig_langs
      for x in self.env['SWIGFLAGS']:
        # obtain the language
        x = x[1:]
        try:
          fun = swig_langs[x]
        except KeyError:
          pass
        else:
          fun(self)

    return super(swig, self).runnable_status()

  def scan(self):
    "scan for swig dependencies, climb the .i files"
    env = self.env

    lst_src = []

    seen = []
    to_see = [self.inputs[0]]

    while to_see:
      node = to_see.pop(0)
      if node in seen:
        continue
      seen.append(node)
      lst_src.append(node)

      # read the file
      code = node.read()
      code = c_preproc.re_nl.sub('', code)
      code = c_preproc.re_cpp.sub(c_preproc.repl, code)

      # find .i files and project headers
      names = re_2.findall(code) + re_3.findall(code)
      for n in names:
        for d in [node.parent]:# + self.generator.includes_nodes 
          u = d.find_resource(n)
          if u:
            to_see.append(u)
            break
        else:
          Logs.warn('could not find %r' % n)

    return (lst_src, [])

# provide additional language processing
swig_langs = {}
def swigf(fun):
  swig_langs[fun.__name__.replace('swig_', '')] = fun
swig.swigf = swigf

def swig_c(self):
  ext = '.swigwrap_%d.c' % self.generator.idx
  flags = self.env['SWIGFLAGS']
  if '-c++' in flags:
    ext += 'xx'
  out_node = self.inputs[0].parent.find_or_declare(self.module + ext)

  if '-c++' in flags:
    c_tsk = self.generator.cxx_hook(out_node)
  else:
    c_tsk = self.generator.c_hook(out_node)

  c_tsk.set_run_after(self)

  ge = self.generator.bld.producer
  ge.outstanding.insert(0, c_tsk)
  ge.total += 1

  try:
    ltask = self.generator.link_task
  except AttributeError:
    pass
  else:
    ltask.set_run_after(c_tsk)
    ltask.inputs.append(c_tsk.outputs[0])

  self.outputs.append(out_node)

  if not '-o' in self.env['SWIGFLAGS']:
    self.env.append_value('SWIGFLAGS', ['-o', self.outputs[0].abspath()])

@swigf
def swig_python(tsk):
  tsk.set_outputs(tsk.inputs[0].parent.find_or_declare(tsk.module + '.py'))

@swigf
def swig_ocaml(tsk):
  tsk.set_outputs(tsk.inputs[0].parent.find_or_declare(tsk.module + '.ml'))
  tsk.set_outputs(tsk.inputs[0].parent.find_or_declare(tsk.module + '.mli'))

@extension(*SWIG_EXTS)
def i_file(self, node):
  # the task instance
  tsk = self.create_task('swig')
  tsk.set_inputs(node)
  tsk.module = getattr(self, 'swig_module', None)

  flags = self.to_list(getattr(self, 'swig_flags', []))
  tsk.env.append_value('SWIGFLAGS', flags)

  # looks like this is causing problems
  #if not '-outdir' in flags:
  #  tsk.env.append_value('SWIGFLAGS', ['-outdir', node.parent.abspath()])

@conf
def check_swig_version(self):
  """Check for a minimum swig version like conf.check_swig_version('1.3.28')
  or conf.check_swig_version((1,3,28)) """
  reg_swig = re.compile(r'SWIG Version\s(.*)', re.M)
  swig_out = self.cmd_and_log('%s -version' % self.env['SWIG'])

  swigver = tuple([int(s) for s in reg_swig.findall(swig_out)[0].split('.')])
  self.env['SWIG_VERSION'] = swigver
  msg = 'Checking for swig version'
  self.msg(msg, '.'.join(map(str, swigver)))
  return swigver

def configure(conf):
  if not conf.find_program('swig', var='SWIG', mandatory=False):
    conf.env.HAVE_SWIG = False
  else:
    conf.env.HAVE_SWIG = True
    conf.env.SWIGPATH_ST = '-I%s'

